An aerodynamic drag component for removably placing on a swung athletic implement may comprise a hollow thin-walled body having an outer profile with a width less than its height and a plurality of spaced-apart perforations with concave lips shaped to scoop air from outside the hollow thin-walled body, through the perforations, and into the hollow thin-walled body to increase aerodynamic drag in a first direction, and convex surfaces opposite the concave lips that are shaped to divert air outside the hollow thin-walled body away from the perforations, to reduce airflow into the hollow thin-walled body to reduce aerodynamic drag in a second direction opposite the first direction, to provide varying aerodynamic drag resistance during a swing. The aerodynamic drag component may freely rotate or freely translate or both on a longitudinally-extending portion of the swung athletic implement. Multiple aerodynamic drag components may be used at once.